With the new halloween update explaining Demoman's origin story, this makes sense.
the demoman lost his eye because of a cursed book that tricked him into opening it when he was a wee lad. Given this is TF2, valve managed to interject a good degree of comedy into it.
What makes me a good Mahou Shoujo? IF I WERE A BAD MAHOU SHOUJO, I WOULDN'T BE SITTING HERE IN MITAKIHARA, KILLING WITCHES NOW WOULD I?
*in battle* LET'S DO IT! *runs through a horde of Witch attacks* Not one of you is gonna survive this!
One crossed wire, one wayward pinch of potassium chlorate, one errant twitch, and DOKKAN!
I got a Wicked Eye, I'm the Cyclops of Mitakihara. They got more fucking witches in the Labyrinth than they've got the likes of me.
So. T'all ya Witches, so proud, so cocksure, prancin' aboot with yer weird bodies. Come and get me I say. I'll be waiting on ya with a whiff of the ol' mermaid's power. I'm a Grimm bloddy fable, with an unhappy bloody end.
*all Witches exterminated* Oh, they're going to have to glue you Witches back together, IN HELL!